1. Paying the older investors their high return rates with money from new investors.
2. The way a Ponzi scheme keeps going is by always getting new investors. At first Madoff got people to really want to be one of his investors. He did this by making it exclusive, so everyone wanted to join. That way he never ran out of new investors. And in order for them to join, they really had to trust him preventing them from doubting him. They didn't catch him because he made fake, but really realistic reports of transactions.
3. Selfish, money hungry(specifically easy-money hungry), and a liar
4. Madoff was apart of the SEC.
5. Madoff grew up in a neighborhood and was raised in a family that wasn't well off. I'm guessing that he always longed to be rich and this was an easy way to do so.